Transmission bursts in the Global System for Mobile Communications (GSM) were originally a single timeslot of Gaussian Minimum Shift Keying (GMSK) modulated data. As the need for higher data rates intensified, GSM was first modified to allow multiple timeslots per transmit frame, which is known as General Packet Radio Service (GPRS). To further increase the data rate, a second modulation scheme was added to GSM. The added modulation scheme is 8-level Phase Shift Keying (8PSK), and the resultant system is referred to as Enhanced General Packet Radio Service (EGPRS). A complication arises because adjacent timeslots within a transmit frame may contain GSMK and 8PSK modulated data and the European Telecommunications Standards Institute (ETSI) standards allow only 37 quarter symbol times (qst), which is approximately 30.5 microseconds, between adjacent timeslots.
Thus, there remains a need for a system and method of transitioning between modulation formats in adjacent timeslots of a transmit frame.